As an image forming apparatus, there is known one including a belt for conveying a recording sheet and an image forming unit which is disposed so as to face a conveying surface of the belt and forms an image on the surface of a recording sheet conveyed by the belt.
In such an image forming apparatus, when a recording sheet fed from the upstream side of the recording sheet conveying direction of the belt comes into contact with the belt, air may be trapped between the recording sheet and the conveying surface of the belt and the recording sheet may partially float from the conveying surface of the belt. If the recording sheet is conveyed in this state to the image forming unit and an image is formed on the surface thereof, the quality of the formed image may lower.
For example, in an electrophotographic image forming apparatus, the image forming unit is configured by a photosensitive member, and a recording sheet is conveyed between the photosensitive member and the conveying surface of the belt, and a transfer bias is applied to a transfer unit and a developing image is transferred (formed) onto the surface of the recording sheet. However, when the transfer is performed in a state that the recording sheet floats from the conveying surface of the belt, there is a possibility that the transfer bias is not sufficiently applied to the floating portion and a so-called void where a developing image is not transferred occurs there, and the image quality lowers.
Therefore, a guiding member is provided which is disposed at an upstream side of the belt in the recording sheet conveying direction; and the guiding member comes into contact with a surface of a recording sheet facing the conveying surface of the belt and guides the tip end portion of the recording sheet to the belt while curving a central portion of the recording sheet in the width direction orthogonal to the conveying direction of the recording sheet so as to protrude toward the conveying surface of the belt.
By the above-described configuration, when a recording sheet is guided by the guiding member while being curved, the recording sheet can be guided to the belt so that, first, the widthwise central portion of the recording sheet curved and protruded toward the conveying surface side comes into contact with the conveying surface of the belt, and while being conveyed, the contact area gradually spreads toward both end sides in the width direction of the recording sheet and air between the conveying surface of the belt and the recording sheet is expelled to both ends. Thus, by expelling air trapped between the recording sheet and the conveying surface of the belt to both end sides, air can be prevented from being trapped between the recording sheet and the conveying surface of the belt and partially floating the recording sheet from the conveying surface of the belt and lowering the image quality.